1. Field of the Invention
The present invention relates to a managing apparatus, an image forming apparatus, a method of controlling the managing apparatus, and a storage medium.
2. Description of the Related Art
A related sheet-feeding device of, for example, a copying machine or a printer includes a plurality of feeding units (including sheet-feed cassettes or sheet-feed trays). Sheets held in the respective feeding units are conveyed to an image forming section by driving respective sheet-feed rollers. However, when the surfaces of the sheet-feed rollers are worn while sheet-feeding is performed, it becomes difficult to feed the sheets. In general, the lives of the sheet-feed rollers tend to be shorter than the life of the main body of the image forming apparatus.
Therefore, it may become necessary to replace parts including the sheet-feed rollers during the time in which the image forming apparatus can still be used.
However, when the sheet-feeding device of the image forming apparatus includes a plurality of feeding units, the rates of use of the feeding units are not the same.
This is because, when the sizes of the sheets held by the respective feeding units are different from each other, the rate of use of any feeding unit for the sheet size that is frequently used is increased, and the rate of use of the any feeding unit for the sheet size that is not frequently used is reduced. In addition, when a plurality of feeding units where sheets of the same size are set are provided, the rates of use of the feeding units may become different from each other due to a feeding method in which, for the purpose of increasing throughput of one printing, sheet-feed operations are sequentially performed starting with the feeding unit where a sheet-conveyance time to the image forming section is short.
By this, the lives of only particular feeding units end quickly, whereas the other sheet-feed cassettes are not frequently used until the lives of these particular feeding units end. Accordingly, the lengths of time required for the feeding units to reach the end of their lives differ from each other. Therefore, a service personnel who replaces parts, such as sheet-feed rollers, of the feeding units of the sheet-feeding device must frequently replace the parts including the sheet-feed rollers. Accordingly, the efficiency with which the service personnel performs maintenance is reduced because the lives of the sheet-feed rollers of the respective feeding units differ from each other.
Accordingly, for example, a method of performing sheet-feeding by integrating a driving time for each of a plurality of sheet-feed rollers and by preferentially selecting a feeding unit corresponding to any sheet-feed roller whose integrated driving time is short is available (refer to Japanese Patent Laid-Open No. 2001-005351).
Another method of performing sheet-feeding by counting and controlling the number of sheets that have been fed for each of a plurality of feeding units and by selecting the feeding unit that has fed a small number of sheets when automatic selection of the feeding unit is set is also available (refer to Japanese Patent Laid-Open No. 2004-149242).
Managing apparatuses that manage sheet-feeding devices using these methods are being considered.
Recent sheet-feeding devices can handle sheets of many sizes and types and allow these sheets to be set at feeding units for feeding the sheets.
However, related methods are not methods that manage the degree of wear of sheet-feed rollers of the feeding units by considering types of sheets that are becoming diversified in recent years.
In particular, the amounts of wear of sheet-feed rollers depend upon the types of sheets. For example, when sheet types differ, the basis weights and the surface properties of the sheets differ. Therefore, when the sheets are fed, the amounts of wear of the sheet-feed rollers also differ. More specifically, when thick sheets are fed, the lives of the sheet-feed rollers end more quickly than when ordinary sheets are fed. In addition, when one-side coated sheets are fed, the lives of the sheet-feed rollers end more quickly than when ordinary sheets are used.
Accordingly, if the difference between the wear amounts of the sheet-feed rollers due to the types of sheets are not considered, the degrees of wear of the sheet-feed rollers cannot be properly known.